Loading-skip-operating mechanism



April 23, 1929.

G. E. WEBBl LOADING SKIP OPERATING MECHANISM Filed March 15. 1926 2 sheets-sheet 2 Patented Apr. 23, 19.29.

UNITED STATES PATENT oFFlcE.

l GEORGE EVANS WEBB, OE MILWAUKEE, WISCONSIN, ASSIGNOB T KOEHRING COH- P ANY, 0F MILWAUKEE, WISCONSIN, .A CORPORATION 0F WISCONSIN.

LOADING-SKIP-'OPERATING MECHANISH.

Application led March 15, 1926. Serial No. 94,824.

This invention has to do with mechanical instrumentalities for raising and lowering heavy bodies. According to the adaptation wherein I have embodiedthe invention as presented hereinafter, a loading skip for concrete mixers is designed to be operated to hoist a load of concrete aggregates and charge the same into a concrete mixer. To illustrate the advantages of the invention in practise, in its special adaptation to which I have referred, I note that large concrete mixing machines at the present time are supplied with the aggregates to be mixed by a skip which is pivoted at one end to the frame of the machine andelevated to an inclined dumping position by means of cables and operating drums connected therewith, the cables leading to the outer or free end of the skip at which it is loaded.

This construction of loading skip and hoisting means possesses serious disadvantages-'from certain viewpoints in that in order to raise the skip to its discharging position, the frame of the machine on which it is mounted must be constructed with a relatively high superstructure on which the cable hoisting drums are mounted, suitable driving means leading to said drums. The high superstructure type of mixing machine offers d1fiiculties in bemg transported from place to place as it will not pass under low bridges, or the like, and must needs be knocked down or folded temporarily, in order to transport it under certain condi- In the carrying out of my invention, I have designed loading skip operating means that does away entirely with the superstructure mounted hoisting devices, suchy as cables, drums, etc., and eliminates the need for employing brakes and special clutches for controlling the ascent and descent of the heavy body of the skip, together with the .load therein, the hoisting of which must be controlled.

To the end above set foith, I employ special lever vlifting devices adapted to be mounted upon the lower art of the main machine frame to lavate t e skip by lifting forces applied from below, as distinguished from the use of the high hoisting cables, connected with the skip from above.

As a special feature associated with the sald liftin devices, I utilize gear mechamsm by w ich the lifting forces are automaticall varied as re ards the ra'tio of power e ciency so that t e movement of the skip will be relatively slow at maximum power when the lifted load is greatest, the speed of action of the lifting devices being accelerated when the load has been moved to a point where reduced power is effective for its movement.

Another feature of novelty is the combination of a known design of variable speed and reverse direction hydraulic transmission provided between the source of power and the lifting devices, and affording a very flexible operating construction to control the up and down movements of the skip or body which is being hoisted and lowered .atdifferent speeds and high operating eiciency.

Still another important feature of the invention resides in the provision of automatic control devices for governing the action of the hydraulic transmission, means directing the movements of the skip, whereby the skip may at ,any time be sto ped in its movement either upwards or ownwards, whereby, when the ski reaches its discharging position which is t e limit of its upward movement, it will be automatically stopped, whereby a similar automatic sto page Will occur when lthe skip reaches the ower limit of its movement at the grade where vit is charged, and whereby in the event of sudden stoppage of the skip by meeting an obstruction in its downward path of movement and automatic shutting oil' of the driving power applied thereto will occur reducing possibility of damage to the skip or breakage .of any of the operating parts.

The invention includes other detail features of construction that will be more fully understood by referring to the following description in conjunction with the accompanying drawings, in which:-

Figure 1 is a side elevation, somewhat diagrammatic in illustration of a concrete mixing machme, and showing the loading skip operating means of the invention, the

Y the parts after the mechanism has reached the said neutralizing position.

Figure 3 is a view similar to Figure 2 wherein the-full lines show the skip just as it reaches the subgrade, and dotted lines the position of the parts depicting the additional movement of the skip raising arms after the skip reaches the subgrade, to neutralize or discontinue the operation of the oil gear.

Figure 4 is a fragmentary view showing more fully by full and 'dotted lines the movement of the lifting levers and relative movement of the lifting arms and points of connection thereof with the skip.

Referring to the drawings, 1 denotes the frame Work of the mixing machine which may be stationary or portable. being illustrated as carried by tract-ion devices 2 and embodying a vertical frame Work 3. The concret-e mixer 4 is the usual drum type mixer having the discharge opening 5 and the receiving or charging opening 6 at which is located the hopper 7.- rl`he mixer 4 is of the gear driven type and is operated by any suitable motor such as a gas engine arranged to drive the same, but not illustrated. Adapted to discharge the concrete aggregates into the hopper 7 of the mixer 4 is the loading skip 8 which is of a/ conventional v type having its upper end reduced in size to form a charging spout 8al adapted to enter the hopper 7 in the discharging operation during which the skip is in its uppermost dotted line position. lVhen receiving the aggregates with which it is charged the skip 8 is ordinarily in its down position resting upon the subg'rade upon which the machine travels. At its discharge upper end the skip 8 is equipped with brackets 9 for pivoting the same at the pivot point 10 to the frame work 3.

My raising and lowering mechanism comprises lifting devices including the lifting levers'll lmounted upon a cross shaft 12 carried by suitable bearings provided on the frame Work 3. The levers 11 are connected by means of arms 13 with the skip 8, said arms 13 being pivotally attached at corresponding ends with the outer correspending ends of the levers 11 by means of a cross shaft or pintle pivot member 14. By using said pivot member 14 as a common pivot between the part of levers 11 and the part of arms 13 side sway when on a. subgrade that is crowned is resisted. ,Y

The levers 11 are equipped at their inner *l ends Which are fixed to the shaft 12, with elliptical gear segments 15 suitably toothed so as to -mesh with elliptical worm gears 16' eecentrically mounted upon a cross shaft 17 l actuated by being geared to one of the gear rings 4a of the mixing drum 4, as by means of the gear shaft 21 and gear' 22 thereon in meshed relation with said rin gear 4a. Intermediate the' shaft 21 and (rive shaft 20 I employ anv hydraulic 'transmission f mechanism of the type known as the oil Y gear, the details of construction of which are,r f5', not shown but will be understood by those versed in the particularart. .The oilgearfl hydraulic transmission generally designated at 23 may be of the types shown by United States Patents #1,489,586 issued March 4th,`

1924, and #1,558,003, issued October Y20th, 1925. The said transmission 23 is acornbined high pressure oil pump and oil motor,

self contained and in one casing and diiven from the shaft 21 aforesaid. The transmission unit is a very flexible one for the pur-f poses of my invention affording a variable and reverse speed Amechanism utilized toA considerable advantage as will be later seen. y

Said transmission 23 is equipped with a.v

direction speed and reverse control member 24 operable by a control lever 25 which has* an oit standing crank arm 26.

By moving the control lever Y right, as seen in Figure 1, the member 24 is operated-to cause action of the transmis- Y sion 23 for driving of the Worm 18 at relatively low speed, said Worm in turn operating the Worm gears 16 and the elliptical segments 15 to thereby cause raising movement of the skip 8. Obviously, the ini-- tial raising movement 'of the skip 8 from the grade line involves a slow motion by reason of the cooperation of the gear elements 16 and 15, said slow motion gradually increasing as'the load in the lever arm of the skip decreases thereby during the latter part of the upward movement of the skip to itsmixer charging position the speed of the movement of the skip is considerably accelerated.

By a movement of the control vlever 25 25 "te um time, and readily accomplished because the skip in its downward movement is relieved of the load of its contents previously charged Y' into the mixer 4. i f

When the control lever is in the full line position of Figure 1, the transmissionv 23 is neutral and no drive is transmitted by the shaft 21 to the worin gears 16 or the worin 18. j The automatic control means governing the I action of stoppage of the skip 8 at certain times may now be set forth, for which purpose attention is especially called to the fact that the lifting arms 13 are connected with the skip 8 by movable bearing means including bearing pins 27 on the sides of the skip which are mounted in blocks or boxes 28` ',.that are adapted to slide in guide ways or slots 29 which areforme'd in the upper outer "ends of the arm 13. It will therefore be appa-rent that there is provided a relative movement between the lifting devices and the skip, or in other words, the connections between these parts are movable connections of which special advantage is taken. From the upper outer end of oneof the arms 13 leads an operating link 30 pivoted at its lower Vend with the arm 26and at its upper end with one of the arms of a bell crank secondary trip lever 36. The ,other arm of the secondary trip lever 36 is in the path of movement of an abutment 37 carried by the skip 8 near its upper end.

`With the foregoing mechanism in mind the complete operation of my control means ma be described.

ssuming that the parts of the invention are in the positions of Figure 1 with the skip 8 supported by'the subgrade at the level of the latter, the control lever 25 will be thrown to the right to render the transmission 23 operative to turn the worin driven gearing' at slow speed. The lifting levers 11 move pivotally upward in starting, raising the lifting arms 13 and initially causing movement of the bearing pins 27 and their bearing boxes downwards or inwards until they reach the inner ends of the guides or slots 29. The relative movement thus produced between the arms 13 and the skip 8 exerts a pull on the link 30 in a rightward direction bringing the connecting pivot point of said link with the trip lever 32 opposite the point of pivotal support 10 of the skip, in which position these parts remain as the skip moves upwardly. Bythis action, moreover, the pin connection 33 of the trip lever 32 is moved to the lower end of the slot 311 of the trip rod 35. The skip 8 of course is moved upwardsas soon as the bearing pins 27 and boxes 28 reach. the inner ends of the slots 29 on the arms 30. Vhcn the skip, the movement of which is accelerated during approximately the last forty degrees of' its movement, has reached its upper limit 75 of movement in which it is fully discharging into the mixer 4 its abutment 37 will have struck the secondary trip lever 36 rocking the latter and causing an uplift movement on the trip rod 35 which raises the 80 arm 26 to its mid position, and sets the control member 24 of the hydraulic transmission 23 zit-neutral. The drive on the skip 8 is thus discontinued.

The operator may then lower the skip 8 by grasping and pulling the lever 25 to the left, `vraising the arm 26 andA starting the transmission 23 to operate the worin gearing in a reverse direction and at double its previous speed of action. Obviously, the operator could not move the lever 25 upwards when the skip is in its upraised limit position because of the abutment between the parts 37 and 36. The cooperation of the parts in this connection therefore affords a safety provision against unauthorized upward lifting of the skip after it has reached its discharging position.

1n the downward movement of the skip, should vthe same for any reason strike an obstruction that would sustain its weight or stop such movement, the levers 11 vand arms 13 would continue to nieve. The bearing boxes 28 and pins 27 would at such time be caused to slide outwardly in the slots 29 or 105 in other words, the arms 13 at their outer ends would move inwardly from and relatively to the skip 8. A pushing force would thus be exerted upon the link member 30 which would cause al contra-clockwise rocking of the primary trip lever 32 sutiiciently to force the trip rod 35 down and neutralize Lthe control member 24, immediately discontinuing the drive upon the levers 11 to stop the skip before possibility of damage or destruction thereof due to meeting the obstruction in its path of movement. Such automatic stopping of the descent of the skip may take place at any point in its downward'travel and when so stopped the 120 operator of the machine cannot movethe lever 25 except to carry the triprod 35 in a downward direction which would set the drive mechanism` .immediately to operate and raise the skip from such obstruction. As soon as this action takes place, the pivot point 31 will be caused to coincide with the pivot axis l() and the operator then may control the skip by leftward movement. of the lever 25 to cause the skip to resume its posi- 130 tion upon the grade. 'Whenever the transmission control member 24 is neutralized, it will be clear that the skip'is held in the position which it has assumed at the time such neutralization takes place.

The subgrade may be considered to constitute an obstruction at the lower limit of movement of the skip 8 and if the operator does not previously throw the hydraulic transmission 23 out of action, the relative movement of the skip and the arms 13 will perform such function by theactionof the link membei` 30 on the primary trip 32.

The foregoing construction and operation of parts involves no action of winding cables, drums, brakes, or even complicated gearing. The lower units will be rotected. by oil tight casings containing amp e lubricant for complete lubrication to reduce wear. The automatic control affords safety features of pronounced advantage as it isimpossible for the skip to be suddenly dropped as often now is the case. The upward and downward movements of the skip are at uniform predetermined speeds, that in raising being much lower than when lowering. It will be quite 'evidentthat the extra superstructure heretofore used for cable lifting arrangement-s of skips is entirely done away with.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is

'1. In combination, a support, a loading device mounted thereon and means for raising and lowering said device comprising a 'power supply source, lifting levers connected with the loading device, an hydraulic transmission unit and a mechanical transmission unit intermediate the power supply source and said lifting levers, the hydraulic transmission unit includingr direction reversing mechanism and the mechanical transmission unit including speed changing devices.

2. In combination, a support, a loading device mounted thereon and means for raising and loweringsaid device comprising a power supply source, lifting levers connected with the loading device, an hydraulic transmission unit and a mechanical transmission unit intermediate the power supply source and said lifting levers, the hydraulic transmission unit comprising a direction and.

speed control member for driving the lifting levers in one direction at low s eed and in another direction at higher spee 3. In combination, a support, a loading device mounted thereon and means for raising and lowering said device comprising a power supply source, lifting levers connected with the loading device, an hydraulic transmission unit and a mechanical transmission unit intermediatethe powerl supply source and said lifting levers, the hydraulic transmission unit comprising a direction and speed control member for driving the lifting levers in vone direction at low speed and in another direction at higher speed, the mechanical transmission unit including a worm driven from the hydraulic transmission unit and variable speed gearing intermediate the worm and the lifting levers'.

4.- In combination, a support, a loading device mounted thereon for up and down movement, lifting means, a movable connection between the lifting means and the loading device, drivingmechanism for the lifting means, and instrumcntalities having operative connection withsaid movable connection and operable by relative movement between the lifting mcans and the loading device for controlling the action of the driving mechanism.

5. In combination, a support, a loading device mounted thereon for up and down movement, lifting means, a movable connection between the lifting means and the loading device, driving mechanism for the lifting means, instrumcntalitics having operative connection with said movable connection and operable by relative movement between the lifting means and the loading dcvice for controlling the action of the driving mechanism,- and direction of movement reversing rmeans cooperative with the driving mechanism for t 1e purpose described.

6. In combination, a loading device, a support upon which said device is mounted, lifting devices for the loading device having movable connection therewith, driving mechanism for the lifting devices and actuating means cXtending between the movable connection of the lifting device and the driving mechanism for discontinuing the operation of said driving mechanism incident to relative movement between the lifting devices *and the loading device.

7. In combination, a loading device, a support upon which said device is mounted, lifting devices for the loading device having movable connection therewith, driving mechanism for the lifting devices and means for discontinuing the operation of said driving mechanism incident to, relative movement of the lifting devices and the loading device, said last means comprising a part operable to stopv the driving mechanism when the loading device meets an obstruction in one direction Vof its movement, and trip devices for stopping said driving mechanism when the loading device reaches a certain limit direction..

l8. In combination, a supporting frame, a loading skip pivoted at one end thereto, lifting levers movably'connected at one end with the loading skip, driving mechanism operably connected with the other ends of the lifting levers to raise and lower them under control, and actuating devices extending between the lifting levers and 'the .drivof movement in an opposite.

imaesc ing mechanism for stopping said driving mechanism at a predetermined point in its movement operable as an incident to relative movement between the lifting levers and skip permitted by the movable connection therebetween.

9. In combinatioma supporting frame, a loading skip pivoted at one end thereon, pivoted lifting levers, arms connected with corresponding ends of the lifting levers and niovabiy connected .lith the loading skip, driving mechanism connected with the opposite corresponding ends of the lifting levers, a control device operatively connected between the lifting levers and the driving mechanism for stopping the operation of said driving mechanism, and trip mechanism associated with said control device and adapted to be operated by the skip at the opposite extreme of its movement, to thereby discontinue the action of the driving mechanism incident to relative movement between the lifting levers and the skip permitted by the movable connection aforesaid.

l0. In combination, a supportingr frame, a loading skip pvoted at one end thereto, lifting levers, arms pivotally connecting said lifting levers wit-li the skip, the pivotal connecting means between the arms and skip comprising a movable connection permitting relative movement of said parts, driving mechanism for thelifting levers, trip means to control said driving mechanism, and an operating member intermediate the trip means and said arms operable incident to relative movement between the latter parts to thereby all'ect operation of said control means.

il. In combination, a supporting frame, a loading skip pivoted at one end thereto, lifting levers, arms ivotally connecting said lifting levers with t e skip, the pivotal connecting means between the arms and skip comprising a. movable connection permitting relative movement of said parts, driv ing mechanism for the lifting levers, trip means to control said driving mechanism, an operating member intermediate the trip means and said arms operable incident to relative movement between the latter parts to thereby affect operation of said control means to sto the driving mechanism during movement o the skip in one direction, and other trip means for actuatin the control means engageablc by the skip itself, to discontinue the operation of the driving mechanism to stop the movement of the skip in an opposite direction.

l2. In combination, a supporting framework, a'skip pivoted at one end thereto, lifting levers for said skip, arms connecting corresponding ends of said levers with the skip, a driving shaft, a worin shaft, a worin on the Worm shaft, change speed gear ing between said worin and the other correspending ends -of the lifting levers compris ing elliptical gear elements in meshing re lation, and an hydraulic transmission unit `Vbetween the driving shaft and the Worm shaft including a control member for revers- .ing the drive from the driving shaft to the worm shaft,

' 13. ln combination, a supporting frame work, a skip pivot-ed at one end thereto, lifting levers for said skip, arms connecting corresponding ends of said levers with the skip, driving mechanism for operating the skip, a hydraulic transmission unit between the driving mechanism and the skip includ ing a control member for reversing the drive, a manual lever for operating said control member, and automatic means to operate the control member including a trip rod, secondary trip means adapted to be actuated by abutment with the skip to operate said control member to stop the transmission operation of the hydraulic transmission, and other trip means connected with the control member for also stopping the operation of the hydraulic transmission, and a movable connection between the skip and the lifting levers for 'operating said other trip means. I

14. In combination, supporting frame work, a'skip pivotedat one end thereto, lift 9 ing levers, arms connected 'with the lifting levers, movable connections between the arms and the. skip permitting relative move ment of the arms and skip, driving mechan nisin for the lifting levers to raise and lower them, a control member for said driv ing mechanism, a trip rod connected with said control member, primary trip means in cliiding a trip lever and link connected with the arms and movable incident to relative movement of the skip and to operate the control member to discontinue the opera tion of the driving mechanism.

l5. In combination, a supporting framework, a. skip pivoted at one end thereto, litti ing levers, arms connected with the lifting levers, movable connections between the arms and the skip permitting relative movement of the arms with respect to the skip, and skip driving mechanism for the lifting levers to raise and lower them, a control member for said driving mechanism, trip rod connected with said control member, primary trip means including a trip lever and link connected with the arms and movable incident to relative movement of the skip and arms to operate the control member to discontinue the operation of the driving mechanism, a manual means to actuate said control member, and a trip lever adapted to be operated by the skip in its movement for also operating the aforesaid trip means to cause the control member to stop the action of the driving mechanism.

16. ln combination, a support comprising Mil ltlll l, frame, a loading device mounted thereon, raising and lowering means for said loading device, stop means for arresting movement of said loading device, and a, shiftable con- 1 5 nection between one of said raising and lowering'means and the loading device, said stopping means being operable through said shiftable connection when an obstacle interposed in the path of movement of said londing device is impinged in the downward 10 movement of the loading device.

In testimony whereof I uix my signature.

GEORGE EVANS WEBB. 

